The present invention relates to watthour meter sockets and, more specifically, to an improved mechanism for simultaneously bypassing the meter and facilitating its release from the socket assembly.
Although there are various approaches to the mounting of a watthour meter in an appropriate socket, the most prevalent approach for the mounting of self-contained watthour meters is to provide meter terminals in the form of conductive blades which protrude from the back of the meter, and provide friction-fit female mountings to receive them. Metal jaws are conventionally provided for this purpose, spring-loaded so as to grip the conductive blades to both hold the meter securely, and to provide good electrical contact.
As such meters are used in great numbers installation, testing, and replacement are common. In order to simplify the installation and replacement procedure various designs have been advanced which will allow a meter to be manually removed and replaced without the use of special tools. In addition, various approaches have been tried for maintaining circuit continuity by bypassing or "jumpering" the meter contacts when the meter is removed.
A number of prior art designs have been developed in order to provide mechanisms which will facilitate the clamping and release of a watthour meter, while simultaneously providing for the "jumpering" of the terminals. In one approach, separate conductive links or jumpers were manually attached by a serviceman to bypass the meter, before its removal. Later developments of meter sockets saw the provision of links within the sockets which could be easily moved to bypassing position wherein they connected adjacent socket terminals. More recently, mechanisms have been provided comprising jumper bars coupled to a lever or the like whereby the jumper bars could be moved into bypassing position across the appropriate terminals, simultaneously relieving the clamping pressure upon the watthour blades so that they could be more easily released. One example of such a construction is disclosed in U.S. Pat. No. 3,003,085 wherein an off-center crossbar, or a crank moves an insulative slide which carries a conductive jumper bar. When in jumpering position the bar causes spring-loaded rigid metal jaws to pivot, spreading them apart and relieving the clamping pressure upon the meter blades. With still another approach spring-loaded jumper bars are forced together to provide the needed bypass by the same "wedging" mechanism which relieves the spring pressure upon the meter blades.
To provide good electrical contact with meter blades, it is highly preferable to form the jaw members from copper alloy. However, owing to the heavy, rigid design of prior art releasable jaw members, the expense of making them of copper alloy is prohibitive. For this reason, such members are conventionally made from aluminum extrusions. Copper alloys are still desirable not only for providing contact with meter blades, but also for obtaining a good contact with a bypass bar which would in some cases at least avoid the need for a separate jumpering mechanism. Therefore, it will be seen that it would be desirable to provide a bypass-type watthour meter socket which utilizes jaws of a thin conductive material such as copper alloy. An additional benefit accompanying the use of thin, flexible material is the ability of the jaws to conform to distorted or misaligned meter blades.
An object of the present invention is to provide a bypass meter socket assembly utilizing releasable jaws which are constructed of thin conductive material.
Another object is to provide an improved meter socket assembly which provides a clear, visible indication when bypassed.
Still another object is to provide an improved meter bypass and release mechanism.